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14311. SPIRITS catalog of IR long period variables
ID:
ivo://CDS.VizieR/J/ApJ/877/110
Title:
SPIRITS catalog of IR long period variables
Short Name:
J/ApJ/877/110
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 417 luminous infrared variable stars with periods exceeding 250 days. These were identified in 20 nearby galaxies by the ongoing SPitzer InfraRed Intensive Transients Survey survey with the Spitzer Space Telescope. Of these, 359 variables have M_[4.5]_ (phase-weighted mean magnitudes) fainter than -12 and periods and luminosities consistent with previously reported variables in the Large Magellanic Cloud (LMC). However, 58 variables are more luminous than M_[4.5]_=-12, including 11 that are brighter than M_[4.5]_=-13, with the brightest having M_[4.5]_=-15.51. Most of these bright variable sources have quasi-periods longer than 1000 days, including four over 2000 days. We suggest that the fundamental period-luminosity relationship, previously measured for the LMC, extends to much higher luminosities and longer periods in this large galaxy sample. We posit that these variables include massive asymptotic giant branch (AGB) stars (possibly super-AGB stars), red supergiants experiencing exceptionally high mass-loss rates, and interacting binaries. We also present 3.6, 4.5, 5.8, and 8.0{mu}m photometric catalogs for all sources in these 20 galaxies.
14312. Spitzer AGN candidates in CDFN
ID:
ivo://CDS.VizieR/J/ApJ/660/167
Title:
Spitzer AGN candidates in CDFN
Short Name:
J/ApJ/660/167
Date:
21 Oct 2021
Publisher:
CDS
Description:
We define a sample of 62 galaxies in the Chandra Deep Field-North whose Spitzer IRAC SEDs exhibit the characteristic power-law emission expected of luminous AGNs. We study the multi-wavelength properties of this sample and compare the AGNs selected in this way to those selected via other Spitzer color-color criteria. Only 55% of the power-law galaxies are detected in the X-ray catalog at exposures of >0.5Ms, although a search for faint emission results in the detection of 85% of the power-law galaxies at the >=2.5sigma detection level. Most of the remaining galaxies are likely to host AGNs that are heavily obscured in the X-ray. Because the power-law selection requires the AGNs to be energetically dominant in the near- and mid-infrared, the power-law galaxies comprise a significant fraction of the Spitzer-detected AGN population at high luminosities and redshifts. The high 24um detection fraction also points to a luminous population. The power-law galaxies comprise a subset of color-selected AGN candidates.
14313. Spitzer and Chandra sources in galactic center
ID:
ivo://CDS.VizieR/J/ApJ/685/958
Title:
Spitzer and Chandra sources in galactic center
Short Name:
J/ApJ/685/958
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have studied the correlation between 2357 Chandra X-ray point sources in a 40x40pc field and ~20000 infrared sources we observed in the corresponding subset of our 2x1.4{deg} Spitzer/IRAC Galactic Center Survey at 3.6-8.0um, using various spatial and X-ray hardness thresholds. The correlation was determined for source separations of less than 0.5", 1", or 2". Only the soft X-ray sources show any correlation with infrared point sources on these scales, and that correlation is very weak. The upper limit on hard X-ray sources that have infrared counterparts is <1.7% (3{sigma}). However, because of the confusion limit of the IR catalog, we only detect IR sources with absolute magnitudes <~1. As a result, a stronger correlation with fainter sources cannot be ruled out. Only one compact IR source, IRS 13, coincides with any of the dozen prominent X-ray emission features in the 3x3pc region centered on Sgr A*, and the diffuse X-ray and IR emission around Sgr A* seems to be anticorrelated on a few-arcsecond scale. We compare our results with previous identifications of near-infrared companions to Chandra X-ray sources.
14314. Spitzer and Herschel observations of debris disks
ID:
ivo://CDS.VizieR/J/ApJ/768/25
Title:
Spitzer and Herschel observations of debris disks
Short Name:
J/ApJ/768/25
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the collisional decay of disk mass and infrared emission in debris disks. With models, we show that the rate of the decay varies throughout the evolution of the disks, increasing its rate up to a certain point, which is followed by a leveling off to a slower value. The total disk mass falls off {prop.to}t^-0.35^ at its fastest point (where t is time) for our reference model, while the dust mass and its proxy -the infrared excess emission- fades significantly faster ({prop.to}t^-0.8^). These later level off to a decay rate of M_tot_(t){prop.to}t^-0.08^ and M_dust_(t) or L_ir_(t){prop.to}t^-0.6^. This is slower than the {prop.to}t.^-1^ decay given for all three system parameters by traditional analytic models. We also compile an extensive catalog of Spitzer and Herschel 24, 70, and 100{mu}m observations. Assuming a log-normal distribution of initial disk masses, we generate model population decay curves for the fraction of stars harboring debris disks detected at 24{mu}m. We also model the distribution of measured excesses at the far-IR wavelengths (70-100{mu}m) at certain age regimes. We show general agreement at 24{mu}m between the decay of our numerical collisional population synthesis model and observations up to a Gyr. We associate offsets above a Gyr to stochastic events in a few select systems. We cannot fit the decay in the far-infrared convincingly with grain strength properties appropriate for silicates, but those of water ice give fits more consistent with the observations (other relatively weak grain materials would presumably also be successful). The oldest disks have a higher incidence of large excesses than predicted by the model; again, a plausible explanation is very late phases of high dynamical activity around a small number of stars. Finally, we constrain the variables of our numerical model by comparing the evolutionary trends generated from the exploration of the full parameter space to observations. Amongst other results, we show that erosive collisions are dominant in setting the timescale of the evolution and that planetesimals on the order of 100 km in diameter are necessary in the cascades for our population synthesis models to reproduce the observations.
14315. Spitzer and high-mass star forming regions
ID:
ivo://CDS.VizieR/J/ApJ/685/1005
Title:
Spitzer and high-mass star forming regions
Short Name:
J/ApJ/685/1005
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Spitzer Space Telescope IRAC and MIPS observations toward a sample of nine high-mass star forming regions at a distance of around 2kpc. Based on IRAC and MIPS 24um photometric results and 2MASS JHKs data, we carry out a census of young stellar objects (YSOs) in a 5'x5' field toward each region. Toward seven out of the nine regions, we detect parsec-sized clusters with around 20 YSOs surrounded by a more extended and sparse distribution of young stars and protostars. For the other two regions, IRAS 20126+4104 and IRAS 22172+5549, the former has the lowest number of YSOs in the sample and shows no obvious cluster, and the latter appears to be part of a larger, potentially more evolved cluster.
14316. Spitzer and NEWFIRM observations of NGC 6334
ID:
ivo://CDS.VizieR/J/ApJ/778/96
Title:
Spitzer and NEWFIRM observations of NGC 6334
Short Name:
J/ApJ/778/96
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents a study of the rate and efficiency of star formation in the NGC 6334 star-forming region. We obtained observations at J, H, and K_s_ taken with the NOAO Extremely Wide-Field Infrared Imager and combined them with observations taken with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope at wavelengths = 3.6, 4.5, 5.8, and 8.0{mu}m. We also analyzed previous observations taken at 24{mu}m using the Spitzer MIPS camera as part of the MIPSGAL survey. We have produced a point source catalog with >700000 entries. We have identified 2283 young stellar object (YSO) candidates, 375 Class I YSOs, and 1908 Class II YSOs using a combination of existing IRAC-based color classification schemes that we have extended and validated to the near-IR for use with warm Spitzer data. We have identified multiple new sites of ongoing star formation activity along filamentary structures extending tens of parsecs beyond the central molecular ridge of NGC 6334. By mapping the extinction, we derived an estimate for the gas mass, 2.2x10^5^M_{sun}_. The heavy concentration of protostars along the dense filamentary structures indicates that NGC 6334 may be undergoing a "mini-starburst" event with {Sigma}_SFR_>8.2M_{sun}_M/yr/pc2 and SFE>0.10. We have used these estimates to place NGC 6334 in the Kennicutt-Schmidt diagram to help bridge the gap between observations of local low-mass star-forming regions and star formation in other galaxies.
14317. Spitzer 3.6 and 4.5um monitoring of 5 stars
ID:
ivo://CDS.VizieR/J/ApJ/805/77
Title:
Spitzer 3.6 and 4.5um monitoring of 5 stars
Short Name:
J/ApJ/805/77
Date:
21 Oct 2021
Publisher:
CDS
Description:
Luminous debris disks of warm dust in the terrestrial planet zones around solar-like stars were recently found to vary, which is indicative of ongoing large-scale collisions of rocky objects. We use Spitzer 3.6 and 4.5um time-series observations in 2012 and 2013 (extended to 2014 in one case) to monitor five more debris disks with unusually high fractional luminosities ("extreme debris disk"), including P1121 in the open cluster M47 (80 Myr), HD15407A in the AB Dor moving group (80Myr), HD 23514 in the Pleiades (120Myr), HD145263 in the Upper Sco Association (10Myr), and the field star BD+20 307 (>~1Gyr). Together with the published results for ID8 in NGC2547 (35Myr), this makes the first systematic time-domain investigation of planetary impacts outside the solar system. Significant variations with timescales shorter than a year are detected in five out of the six extreme debris disks we monitored. However, different systems show diverse sets of characteristics in the time domain, including long-term decay or growth, disk temperature variations, and possible periodicity.
14318. Spitzer 70 and 160um observations in xFLS
ID:
ivo://CDS.VizieR/J/AJ/131/250
Title:
Spitzer 70 and 160um observations in xFLS
Short Name:
J/AJ/131/250
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 70 and 160{mu}m observations from the Spitzer extragalactic First Look Survey (xFLS). The data reduction techniques and the methods for producing co-added mosaics and source catalogs are discussed. Currently, 26% of the 70{mu}m sample and 49% of the 160{mu}m-selected sources have redshifts. The majority of sources with redshifts are star-forming galaxies at z<0.5, while about 5% have infrared colors consistent with active galactic nuclei. The observed infrared colors agree with the spectral energy distributions (SEDs) of local galaxies previously determined from IRAS and Infrared Space Observatory data.
14319. Spitzer Archival Far-Infrared Extragalactic Survey (SAFIRES) MIPS 160 micron Catalog
ID:
ivo://irsa.ipac/Spitzer/Catalog/SAFIRES/SAFIRES160
Title:
Spitzer Archival Far-Infrared Extragalactic Survey (SAFIRES) MIPS 160 micron Catalog
Short Name:
SAFIRES160
Date:
01 Oct 2018 20:27:18
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Spitzer Archival FIR Extragalactic Survey (SAFIRES) is an offshoot of the Spitzer Space Telescope Enhanced Imaging Products (SEIP). SAFIRES applies the SEIP project's methods to the remaining two MIPS bands, located at far-infrared wavelengths of 70 and 160 microns. Due to the complexity of far-infrared observations, these bands require an expansion of SEIP's standard pipeline through the addition of reprocessing tools. These additional steps are required to remove obvious artifacts before extracting useful measurements. As a result, these bands were not included in the SEIP project, but were later funded through an additional NASA Astrophysics Data Analysis Program (ADAP) grant. To ensure high reliability, the SAFIRES sample includes no fields near the Galactic disk; these observations comprised more than half of the area observed by Spitzer, but the practical drawbacks of Galactic contamination would inhibit the ability to maintain the level of reliability desired in the SAFIRES products. As with SEIP, the SAFIRES source lists contains no extended sources. The remaining sample comprises nearly 1132 fields spanning almost 180 square degrees of sky.
14320. Spitzer Archival Far-Infrared Extragalactic Survey (SAFIRES) MIPS 70 micron Catalog
ID:
ivo://irsa.ipac/Spitzer/Catalog/SAFIRES/SAFIRES70
Title:
Spitzer Archival Far-Infrared Extragalactic Survey (SAFIRES) MIPS 70 micron Catalog
Short Name:
SAFIRES70
Date:
01 Oct 2018 20:27:18
Publisher:
NASA/IPAC Infrared Science Archive
Description:
The Spitzer Archival FIR Extragalactic Survey (SAFIRES) is an offshoot of the Spitzer Space Telescope Enhanced Imaging Products (SEIP). SAFIRES applies the SEIP project's methods to the remaining two MIPS bands, located at far-infrared wavelengths of 70 and 160 microns. Due to the complexity of far-infrared observations, these bands require an expansion of SEIP's standard pipeline through the addition of reprocessing tools. These additional steps are required to remove obvious artifacts before extracting useful measurements. As a result, these bands were not included in the SEIP project, but were later funded through an additional NASA Astrophysics Data Analysis Program (ADAP) grant. To ensure high reliability, the SAFIRES sample includes no fields near the Galactic disk; these observations comprised more than half of the area observed by Spitzer, but the practical drawbacks of Galactic contamination would inhibit the ability to maintain the level of reliability desired in the SAFIRES products. As with SEIP, the SAFIRES source lists contains no extended sources. The remaining sample comprises nearly 1132 fields spanning almost 180 square degrees of sky.

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